heart lab f11

8/6/2019 Heart Lab F11

http://slidepdf.com/reader/full/heart-lab-f11 1/3

1

BIO 202

Heart Lab

Goals for this activity:

· Identify the principal structures of the heart

· Identify the great vessels the bring blood to and from the heart

· Identify principal histological features of heart muscle, vein and artery walls· Identify the components of an ECG wave

Identify the Following:

External Cardiac Anatomy (human & sheep hearts)

· Pericardium

o Double membrane that encases the heart within the thorax.

· Wall of the heart

o Made-up of three layers, you cany see the epicardium on the surface.

Epicardium - thin outer layer of the heart

Myocardium – thick muscular layer

Endocardium – thin layer lining the interior chambers of the heart

· Apex - Inferior pointy part of the heart.

· Base

o Flat surface outside of right ventricle, medial to the apex.

· Pulmonary artery

o Artery leaving the right ventricle going to the lungs, anterior to the aorta.

· Aorta

o Artery leaving the left ventricle, its walls are thicker than the pulmonary artery.

· Superior and Inferior Vena Cava

o Veins entering the right atrium, returning blood from the upper and lower body.

· Pulmonary veins

o 4 veins entering the left atrium from the lungs (2 from each lung)

· Atria and Auricles (right and left)

o Small chambers in the superior portion of the heart with ‘flaps’ on the outside.

· Ventricles (right and left)

o Main pumping portion of the heart, left side is much thicker than the right.

· Coronary arteries

o Arteries on the surface of the heart.

· Coronary sinus

o Enlarged reservoir on the posterior aspect of the heart where coronary veins drain.

· Interventricular sulcus

o Groove between ventricles where the left anterior descending artery travels.



2

Coronary Arteries (Human Hearts)

· Main coronary artery

o Short segment immediately

coming off the aorta.

· Left circumflex artery

o The artery that stays high

and circles around to theback.

· Left anterior descending artery

(anterior interventricular artery)

o The artery that goes

straight down the anterior

surface.

· Right coronary artery

o The artery that branches to

the right side of the heart.

Internal Cardiac Anatomy (in order of blood flow)

· Superior and Inferior Vena Cava

o Veins entering the right atrium, returning blood from the upper & lower body.

· Right atrium

o Where the blood first returns to the heart from the body.

o Musculi pectinati – mesh-like musculature lining the right atrium

o Fossa ovalis – previous location of the foramen ovale (shortcut to left atrium)

· Tricuspid valve or right atrioventricular valve

o Three flaps attached to ‘strings’ separating the right atrium from right ventricle.

o Chordae tendineae - strings that attach the valve to the musculatureo Papillary muscles –protruding musculature ‘holding on’ to the ‘strings’.

· Right ventricle

o Muscular chamber that receives oxygenated blood from the right atrium and pumps blood to the lungs

via the pulmonary trunk and arteries.

o Trabeculae carnea – web-like musculature lining the chamber

o Chordae tendinae – strings that attach the valve to the musculature

o Papillary muscles – protruding musculature ‘holding on’ to the ‘strings’

· Pulmonary semilunar valve

o Three ‘cups’ separating the right ventricle from the pulmonary artery.

· Pulmonary trunk→ splits into R & L pulmonary arteries

o Artery leaving the right ventricle going to the lungs.· Lungs

o These aren’t on your heart. This is just to keep this list in blood-flow order.

· Pulmonary veins

o 4 veins entering the left atrium from the lungs (2 from each lung)

· Left atrium

o Where the blood returns to the heart from the lungs.

· Mitral valve or left atrioventricular valve

o Two flaps attached to ‘strings’ separating the left atrium from left ventricle.

o Chordae tendineae – strings that attach the valve to the musculature

o Papillary muscles – protruding musculature ‘holding on’ to the ‘strings’.



3

· Left ventricle

o Muscular chamber that receives oxygenated blood from the left atrium and pumps blood to the body via

the aorta.

o Thick myocardium

o Septum – this is also in the right ventricle, it separates the two ventricles

· Aortic semilunar valve

o Three ‘cups’ separating the left ventricle from the aorta.· Aorta

o Artery leaving the left ventricle, it is thicker than the pulmonary artery.

Dissection Procedure

1. Cut the apex off the heart about 1-1 ½ inch from the bottom. This is so you can view the differences between

the right and left ventricles in terms of myocardial thickness.

2. Cut upwards toward the atria along the surface of the septum inside the right ventricle (it will be easier cutting

on the right side. Do this very carefully so you don’t cut the chordae tendinae. . Open up the right ventricle so

you can look upward toward the tricuspid valve (right atrioventricular valve). Observe the trabeculation (strappy

muscles inside the RV) and the parts of the valve.

3. Cut open the pulmonary artery starting from the outer end and cut toward the right ventricle. Do this carefully

because you just want to open the PA enough so you can see the semilunar valve and the 3 little cusps.

4. Carefully open up the right atrium so you can see the inner surface. Do this by cutting from the inferior vena

cava and transverse across toward the atrial septum. This should allow for a superior view of the tricuspid valve

and the fossa ovalis.

5. Now you have a handle on most parts, cut the left ventricle as you wish to investigate more.

Digital Electrocardiogram (ECG)

· P wave

o Electrical indication of activation NOT contraction of atria. Atrial contraction occurs after the P wave, as

the P wave is the electrical stimulus which ‘turns on’ the muscle.

· QRS complex

o Electrical indications of atrial repolarization and ventricular activation (depolarization), NOT muscular

contration. This is the stimulus that indicates how the ventricles are being ‘activated’ and then the

ventricles will contract AFTER the QRS complex occurs.

o Q – initial downward deflection

o R – large upward spike

o S – downward deflection after R wave spike

· T wave

o Electrical indication of repolarization or relaxation of the ventricles. The ventricles are relaxing during

this time.

heart lab f11

Documents